Paints and methods of manufacturing same



Karl Culemeyer, Hambnrg-Langenfelde, Germany, assignor to WillySpangenberg & Co., Hamburg-Eidelstedt, Germany, a company of Germany NoDrawing. Original application September 9, 1950,

Serial No. 184,115. Divided and this application January 16, 1952,Serial No. 266,793

Claims priority, application Germany September 10, 1949 11 Claims. (Cl.260-404) This invention relates to paints, paint bases and methods ofmanufacturing the same. More particularly it pertains to the preparationof substances adapted for utilization as paint bases and for affordingimproved paint compositions, embracing within its purview the novelproducts obtained. In its preferred aspects, the procedural features andattainable products of the invention are eifected through the adaptationof tallic or tall oil. The present application is a division of myco-pending application Serial No. 184,115 filed September 9, 1950, whichhas matured to Patent No. 2,781,386.

The term tallic oil is synonymously referred to herein as tall oil. Itwill be understood that the said tallic or tall oil is intended todesignate throughout this specification the liquid resinous typesubstance which is referred tates Patent Q F to as waste product in themanufacture of cellulose from a pine wood.

An object of the present invention is to produce quickly drying paintbases or paints of high weather resistance.

Another object is to improve the drying qualities of paint bases orpaints containing tallic oil fatty esters, the said dryingcharacteristics being otherwise generally insuflicient due to theabsence of linolenic acid and the presence of a high content of oleicacid in the fatty acids.

A further object is to increase the molecular size of tallic oil fattyacid esters of increased molecular size and manifesting enhanced dryingqualities of paint bases or paints containing these substances.

An important object is to provide paints which will not yellow with age.

An additional object is the provision of paints or paint bases derivedfrom a fatty acids containing composition which is substantially free oflinolenic acid, whereby such paints will not yellow or tarnish with age.

Another object is the provision of paints which afford increasedwaterproof characteristics and resistance to inclement weather.

Other objects of the present invention will become apparent in thecourse of the following description presenting the features and detailsof the invention by way of illustration and not limitation.

In accomplishing the objects of the present invention it was founddesirable to convert practically pure fatty acids and/ or pure resinacids of tallic or tall oil, obtained for example in the course of highvacuum distillation of raw tallic oil into predetermined types ofesters.

Particularly good results are obtained when polyhydric alcohol esters ofpure tallic oil fatty acids are converted with dior polyisocyanates by apolyaddition reaction. It was found that it is advantageous to proceedby producing partial esters of these fatty acids which contain less thanone free hydroxyl group to one ester molecule, such as an ester whereinthree ester molecules have one free hydroxyl group. Desirably the tallicoil fatty acids are esterified with polyvalent alcohols to produce apar- Patented Nov. 5, 1957 tial ester product, as aforesaid, having freehydroxyl groups, and the ester product is reacted with an amount ofpolyisocyanate adapted to provide isocyanate groups corresponding innumber with the free hydroxyl groups of the ester product. If theseesters are converted with an equivalent amount of a dior polyisocyanate,then the resulting oil-like product will afford optimum drying qualitiesand superior properties with respect to water and light resistance. Itis advantageous to use small amounts of polyisocyanates, for example, adiisocyanate, such as p-toluylene-diisocyanate, such amounts beingsmaller than those corresponding to the stoichiometric relationship ofone molecule diisocyanate to two molecules ester, each with a freehydroxyl group, since in addition to the low costs of the process, thedanger of gelatinization during conversion with diisocyanate, as aresult of unduly progressed polyaddition is considerably diminished, anda yellowing which often takes place when large amounts of diisocyanateare used is avoided entirely.

It was found advantageous to use dior triisocyanates for combinationpurposes. Particularly desirable results have been obtained by the meetless than or not to exceed approximately six percent by weight of diortriisocyanate related to the ester. Thus lacquer oils were producedwhich after being siccativated and diluted in the usual manner producevarnishes of excellent weather and water resistance, and upon beingrubbed up With white pigments, produce pure white paints which will notyellow, despite being exposed to adverse Weather conditions.

Pursuant to the latitudes of the invention, it is possible to produceexcellent paint bases orpaints from esters containing free hydroxylgroups, of tallic oil fatty acids, tallic oil resin acids and/or dryingor half-drying oils reacted with the polyvalent alcohols, theesterification or transesterification being carried out to an extentsuch that the esters have a hydroxyl number Within the range of about 5to 65, and whereby these partial esters are coupled withpolyisocyanates, i. e., isocyanates with more than one cyanate group inthe molecule. The present invention also includes adducts capable ofsplitting, which are so-called masked isocyanates.

It was found that for the manufacture of partial esters it isadvantageous to employ tallic oil, or its components, such as tallic oildistillates, pure tallic oil fatty acids, pure tallic oil resin acids,esters thereof, or condensation or polymerization products, or mixturesof the latter.

The invention will appear more clearly from the following example, givensolely by way of illustration and not by way of limitation.

Example 1000 kilograms pure tall oil fatty acids'with a content of 96%oleic acid and linoleic acid are esterified with 140 kilogramspentaerythritol at 280 C. at low pressure, starting with an acid valueof 30, until the acid value has reached 8. Then the product is cooled toC. and reacted with 37 kilograms p-toluylene-diisocyanate. Thistemperature is maintained for two hours while the substances arestirred, and thereupon the reaction prodnot is siccativated and dilutedin the usual manner. This product results in a well drying paint of highresistance against adverse weather and water which upon being rubbed upwith white pigments produces pure white colors which upon application donot chalk off or become yellow.

Thus in accordance with the present invention, tallic oil, otherwiseknown as tall oil, is utilized in producing an enhanced coatingcomposition of a type manifesting optimum attributes as a paint base orpaint composition. As a summary indication of a preferred embodiment oradaptation thereof, tall oil, desirably in a substantially pure state,such as that obtainable by the high vacuum distillation of raw tall oil,is reacted with polyhydric al cohol, the reagents .beingin regulatedproportion ,to afford .a .partially esterified product having freehydroxyl groups, the contentof the latter being less than one freehydroxyl group to one ester molecule, with the said esterified productdesirably having a hydroxyl number within the approximate range of 5 to65. The aforesaid partially esterified product is in turn reacted with arelatively small amount of polyisocyanate, below that which may effectgelation of the ester product. Desirably the quantity of polyisocyanate,based .on the, weight of the ester -product,.is sufiicient to provideisocyanate groups substantially corresponding with the number of freehydroxyl groups .in .the partially esterified product. Indicative of aneffective molar relationship is an amount of po'lyisocyanate .below thatcorresponding .to the stoichiometric relationship of one molecule of theisocyanate to two molecules of the ester product.

The ultimate product attained, comprising that resulting from thereaction of the aforesaid tall oil esterified polyhydric alcohol with apolyisocyanate in accordance with the present invention, affordsenhanced color fastness and water resistance, as well as optimum dryingcharacteristics, as a coating composition. In addition, an'irnprovedstability is afforded with respect to premature gelatinization and inconnection with weather resistance generally.

While the invention herein has been illustratively described inaccordance with desirable and preferred procedural adaptations, it willbe apparent that many changes may be made in the details and featuresthereof without departing from the essence or latitude of the inventionas defined in the following claims.

What is claimed is:

'1. The process of manufacturing a drying paint base, which comprisesesterifying substantially pure tall oil fatty acids with a polyhydricalcohol to produce a polyhydric alcohol ester product which containsless than one free hydroxyl group to one ester molecule and having ahydroxyl number within the approximate range of 5 to 65, and reactingthe ester product with a polyisocyanate in an amount less than thatcorresponding to the stoichiometric relationship of one molecule of thepolyisocyanate to two ester molecules and in sufiicient quantity toprovide isocyanate groups substantially corresponding with the numberofffree hydroxylgroups in the ester product.

'2. The process ,as in claim 1, wherein the polyisocyanate is asubstance from the group consisting of diisocyanates and triisocyanates.

3. The process as in claim 2, wherein the amount of isocyanate is below6% by weight of the ester product.

4. The process as in claim 2, wherein the polyhydric alcohol esterproduct comprisesthree ester molecules to one 'free hydroxyl group.

5. The process as in claim 3, wherein the tall oil fatty acids comprisea content of approximately 96% oleic acid ,and linoleic acid.

6. A process for preparing a drying paint composition comprising theprocess as in claim 3, wherein the reaction product :is siccativated,diluted to a desirable paint viscosity and admixed 'with a predeterminedpigment.

7. The process as in claim 5, wherein the polyhydric alcohol ispentaerythritol and the diisocyanate is ptoluylene-diisocyanate.

8. The process as in claim 7, wherein the tall oil fatty acids areesterified with the pentaerythritol at a temperature of approximately280 C. and at reduced pressure, until the initial acid value of 30isreduced to an acid value of approximately 8,'the'resultant esters beingthen cooled to approximately C., and reacted with thep-toluylenc-diisocyanate for approximately two hours, the reagents beingreacted in the relative proportions conforming .with therelationship of1000 kilograms of tall oil fatty acids and '37 kilograms ofp-toluylene-diisocyanate.

9. A process for preparing a drying paint composition comprisingtheprocess as in claim 8, wherein the reaction product is siccativated,diluted to a desirable paint viscosity, and admixed with a whitepigment.

10. The product resulting from the process of claim 5.

11. The productresulting from the process of claim 7.

References Cited in the fileof this patent UNITED STATES PATENTS2,214,784 Wayne Sept. 17, 1940 2,358,475 Pratt et al. Sept. 19, 19442,365,300 Segessemann Dec. 19, 1944 2,523,309 Kester Sept. 29, 1950OTHER REFERENCES Bailey: Oil andFat Products, Interscience Publishing,Inc., New York city, 1945, pages 380381.

Otficial Digest, No. .251, December 1945, pages 490-492.

Bayer: Modern Plastics, June 1947, pages 149-152.

1. THE PROCESS MANUFACTURING A DRYING PAINT BASE, WHICH COMPRISESESTERIFYING SUBSTANTIALLY PURE TALL OIL FATTY ACIDS WITH A POLYHYDRICALCOHOL TO PRODUCE A POLYHYDRIC ALCOHOL ESTER PRODUCT WHICH CONTAINSLESS THAN ONE FREE HYDROXYL GROUP TO ONE ESTER MOLECULE AND HAVING AHYDROXYL NUMBER WITHIN THE APPROXIMATE RANGE OF 5 TO 65, AND REACTINGTHE ESTER PRODUCT WITH A POLYISCOYANATE IN AN AMOUNT LESS THAN THATCORRESPONDING TO THE STOICHIOMETRIC RELATIONSHIP OF ONE MOLECULE OF THEPOLYISOCYANATE TO TWO ESTER MOLECULES AND IN SUFFICIENT QUANTITY TOPROVIDE ISOCYANATE GROUPS SUBSTANTIALLY CORRESPONDING WITH THE NUMBER OFFREE HYDROXYL GROUPS IN THE ESTER PRODUCT.